The device may be used as a two-dimensional position measuring device, indicating transmitter or desired position value transmitter for an area of a few square centimetres.
Known embodiments of desired value transmitters are used, for example, for remote control purposes as a mouse or a "trackball" in computer technology, or as "joystick" in model construction.
The principle of construction of a "mouse" or of a "trackball" consists of two incremental rotary encoders arranged orthogonally and a rubberized ball supported rotatably in a receiving mounting and bearing on both rotary encoder axes. By means of rotating the ball in any desired direction, either one or both rotary encoder axes are changed simultaneously, so that a specific rotational change of the rotary encoder corresponds to the angle of the rotary movement of the ball. A signalprocessing stage for supplying evaluation pulses is usually connected to the circuitry supplying pulses, for evaluation.
Instead of having rotary encoders, a "joystick" has two potentiometers which are coupled to a control lever via a universal joint. Each position of the control lever has allocated to it a corresponding position of the potentiometer slides. The voltage values of each potentiometer are fed to an evaluation circuit.
Disadvantageous in the case of both the above-described concepts are both the relatively high manufacturing costs (material and production) and also the high energy consumption.